We are constantly asked why concrete slabs sink, and how to prevent them from doing it again. The answer is simple, in 99% of the cases the culprit is poor drainage at the slab. What this means is that if you can see the bottom of your concrete, you have negative drainage, and if you have negative drainage, the soil beneath you slab will be depleted leaving you with a situation that will cause voids beneath your concrete and will cause water to flow towards the foundation of your home, which will make its way into the basement and may even cause serious problems with the integrity of your foundation.

Check placement of downspouts - Sometimes gutters need to be moved in order to keep water from undermining driveway or walkway slabs.

Landscaping - Trees that have been removed will eventually rot down and cause a low spot in your yard, this could eventually be a place where water will collect and have no way out, creating a bigger void near pool decking, driveways and walkways.

Seal cracked concrete - Each time it rains, that water is seeping down in between cracked concrete and eroding soil underneath. If enough soil is eroded out, that slab or concrete section will drop because it no longer has the support needed below.